Federal Register: April 2, 2009 (Volume 74, Number 62)
DOCID: fr02ap09-7 FR Doc E9-5981
DEPARTMENT OF THE INTERIOR
Veterans Employment and Training Service
CFR Citation: 50 CFR Part 17
RIN ID: RIN 1018-AW41
FWS ID: [FWS-R3-ES-2008-0120; 92220-1113-000; ABC Code: C6]
NOTICE: Part II
DOCID: fr02ap09-7
DOCUMENT ACTION: Final rule.
SUBJECT CATEGORY:
Endangered and Threatened Wildlife and Plants; Final Rule To Identify the Western Great Lakes Populations of Gray Wolves as a Distinct Population Segment and To Revise the List of Endangered and Threatened Wildlife
DATES: This rule becomes effective on May 4, 2009.
DOCUMENT SUMMARY:
We, the U.S. Fish and Wildlife Service (Service or USFWS) identify the Western Great Lakes (WGL) Distinct Population Segment (DPS) of the gray wolf (Canis lupus). The geographic extent of this DPS includes all of Minnesota, Wisconsin, and Michigan; the eastern half of North Dakota and South Dakota; the northern half of Iowa; the northern portions of Illinois and Indiana; and the northwestern portion of Ohio. We also revise the List of Endangered and Threatened Wildlife established under the Endangered Species Act of 1973, as amended (Act) by removing gray wolves within the WGL DPS. We are taking these actions because available data indicate that this DPS no longer meets the definitions of threatened or endangered under the Act. The threats have been reduced or eliminated, as evidenced by a population that is stable or increasing in Minnesota, Wisconsin, and Michigan, and greatly exceeds the numerical recovery criteria established in its recovery plan. Completed State wolf management plans will provide adequate protection and management of the WGL DPS after this revision of the listing. This final rule removes this DPS from the lists of Threatened and Endangered Wildlife, removes the currently designated critical habitat for the gray wolf in Minnesota and Michigan, and removes the current special regulations for gray wolves in Minnesota.
On April 16, 2007, three parties filed a lawsuit against the U.S. Department of the Interior (Department) and the Service, challenging the Service's February 8, 2007 (72 FR 6052), identification and delisting of the WGL DPS. On September 29, 2008, the U.S. District Court for the District of Columbia ruled in favor of the plaintiffs (Humane Society of the United States v. Kempthorne, No. 1:07CV00677 (D.D.C.). In that ruling the court vacated and remanded the Service's application of the February 8, 2007 (72 FR 6052), final delisting rule for the WGL DPS of the gray wolf. On remand, the Service was directed to provide an explanation as to how simultaneously identifying and delisting a DPS is consistent with the Act's text, structure, policy objectives, legislative history, and any relevant judicial interpretations. This final rule addresses the September 29, 2008, court ruling.
SUMMARY:
Interior Department, Fish and Wildlife Service,
SUPPLEMENTAL INFORMATION
Background
Biology and Ecology of Gray Wolves
For a discussion of the biology and ecology of gray wolves and general recovery planning efforts, see the proposed WGL wolf rule published on March 27, 2006, (71 FR 1526615305) and available on our World Wide Web site.
Recovery Criteria
The 1978 Recovery Plan for the Eastern Timber Wolf (Recovery Plan) and the 1992 revised Recovery Plan (Revised Plan) contain the same two delisting criteria. The first delisting criterion states that the survival of the wolf in Minnesota must be assured. We, and the Eastern Timber Wolf Recovery Team (Peterson in litt. 1997, 1998, 1999a, 1999b), have concluded that this first delisting criterion remains valid. It addresses a need for reasonable assurances that future State, Tribal, and Federal wolf management and protection will maintain a viable recovered population of gray wolves within the borders of Minnesota for the foreseeable future.
Although the Recovery Plan's recovery criteria predate the scientific field of conservation biology, the conservation principles of representation (conserving the genetic diversity of a taxon), resilience (the ability to withstand demographic and environmental variation), and redundancy (sufficient populations to provide a margin of safety) were incorporated into these criteria. Maintenance of the Minnesota wolf population is vital because the remaining genetic diversity of gray wolves in the eastern United States was carried by the several hundred wolves that survived in the State into the early 1970s. The Recovery Team insisted that the remnant Minnesota wolf population be maintained and protected to achieve wolf recovery in the eastern United States. The successful growth of that remnant population has maintained and maximized the representation of that genetic diversity among gray wolves in the WGL DPS. Furthermore, the Recovery Plan established a planning goal of 1,2501,400 animals for the Minnesota wolf population (USFWS 1992, p. 28), which would increase the likelihood of maintaining its genetic diversity over the long term. This large Minnesota wolf population also provides resiliency to reduce the adverse impacts of unpredictable demographic and environmental events. Furthermore, the Recovery Plan specifies a wolf population that is spread across about 40 percent of the State (Zones 1 through 4) (USFWS 1992, p. 28), adding a geographic component to the resiliency of the Minnesota wolf population.
The second delisting criterion in the Recovery Plan states that at
least one viable wolf population should be reestablished within the
historical range of the eastern timber wolf outside of Minnesota and
Isle Royale, Michigan. The second population enhances both the
resiliency and redundancy of the recovery program. The Recovery Plan
provides two options for reestablishing this second population. If it is an isolated population, that is, located
[[Page 15071]]
more than 100 miles (160 km) from the Minnesota wolf population, the
second population should consist of at least 200 wolves for at least 5
years (based upon latewinter population estimates) to be considered
viable. Alternatively, if the second population is located within 100
miles (160 km) of a selfsustaining wolf population (for example, the
Minnesota wolf population), it would be considered viable if it
maintained a minimum of 100 wolves for at least 5 years. Such a nearby
second population would be viable at a smaller size, because it would
exchange wolves with the Minnesota population (that is, they would
function as a metapopulation), thereby bolstering the smaller second population genetically and numerically.
The Recovery Plan does not specify where in the eastern United States the second population should be reestablished. Therefore, the second population could be located anywhere within the triangular MinnesotaMaineFlorida area covered by the 1978 Recovery Plan and the 1992 Revised Recovery Plan, except on Isle Royale (Michigan) or within Minnesota. The 1992 Revised Recovery Plan retained potential gray wolf reestablishment areas in northern Wisconsin, the upper peninsula (UP) of Michigan, the Adirondack Forest Preserve of New York, a small area in eastern Maine, and a larger area of northwestern Maine and adjacent northern New Hampshire (USFWS 1992, pp. 5658). Neither the 1978 nor the 1992 recovery criteria suggest that the restoration of the gray wolf throughout all or most of its historical range in the eastern United States, or to all of these potential reestablishment areas, is necessary to achieve recovery under the Act.
In 1998, the Eastern Timber Wolf Recovery Team clarified the
application of the delisting criterion for the second population to the
wolf population that had developed in northern Wisconsin and the
adjacent UP. The Recovery Team recommended that the numerical delisting
criterion for the WisconsinMichigan population will be achieved when 6
consecutive latewinter wolf surveys document that the population
equals or exceeds 100 wolves (excluding Isle Royale wolves) for the 5
consecutive years between the 6 surveys (Peterson in litt. 1998). This
second population is less than 200 miles from the Minnesota wolf population.
Recovery of the Gray Wolf in the Western Great Lakes Area
Minnesota Recovery
During the pre1965 period of wolf bounties and legal public trapping, wolves persisted in the remote northeastern portion of Minnesota, but were eliminated from the rest of the State. Estimated numbers of Minnesota wolves before their listing under the Act in 1974 include 450 to 700 in 195053 (Fuller et al. 1992, p. 43, based on data in Stenlund 1955, p. 19), 350 to 700 in 1963 (Cahalane 1964, p. 10), 750 in 1970 (Leirfallom 1970, p. 11), 736 to 950 in 197172 (Fuller et al. 1992, p. 44), and 500 to 1,000 in 1973 (Mech and Rausch 1975, p 85). Although these estimates were based upon different methodologies and are not directly comparable, each puts the prelisting abundance of wolves in Minnesota at 1,000 or less. This was the only significant wolf population in the United States outside Alaska during those time periods.
After the wolf was listed as endangered under the Act, the Minnesota population estimates increased (see Table 1 below). Mech estimated the population to be 1,000 to 1,200 in 1976 (USFWS 1978, pp. 4, 5052), and Berg and Kuehn (1982, p. 11) estimated that there were 1,235 wolves in 138 packs in the winter of 197879. In 198889, the Minnesota Department of Natural Resources (MN DNR) repeated the 197879 survey and also used a second method to estimate wolf numbers in the State. The resulting independent estimates were 1,500 and 1,750 wolves in at least 233 packs; the lower number was derived by a method comparable to the 197879 survey (Fuller et al. 1992, pp. 5051).
During the winter of 199798, a statewide wolf population and
distribution survey was repeated by MN DNR, using methods similar to
those of the two previous surveys. Field staff of Federal, State,
Tribal, and county land management agencies and wood products companies
were queried to identify occupied wolf range in Minnesota. Data from 5
concurrent radio telemetry studies tracking 36 packs, representative of
the entire Minnesota wolf range, were used to determine average pack
size and territory area. Those figures were then used to calculate a
statewide estimate of wolf and pack numbers in the occupied range, with
single (nonpack) wolves factored into the estimate (Berg and Benson 1999, pp. 12).
Table 1Gray Wolf Winter Populations in Minnesota, Wisconsin, and Michigan (Excluding Isle Royale) From 1976
Through 2006
[Note that there are several years between the first three estimates]
WI & MI
Year Minnesota Wisconsin Michigan Total
1976..................................................... 1,0001,200 ........... ........... ...........
197879.................................................. 1,235 ........... ........... ...........
198889.................................................. 1,5001,750 31 3 34
198990.................................................. .............. 34 10 44
199091.................................................. .............. 40 17 57
199192.................................................. .............. 45 21 66
199293.................................................. .............. 40 30 70
199394.................................................. .............. 57 57 114
199495.................................................. .............. 83 80 163
199596.................................................. .............. 99 116 215
199697.................................................. .............. 148 113 261
199798.................................................. 2,445 180 139 319
199899.................................................. .............. 205 169 374
19992000................................................ .............. 248 216 464
200001.................................................. .............. 257 249 506
200102.................................................. .............. 327 278 604
200203.................................................. .............. 335 321 656
200304.................................................. 3,020 373 360 733
200405.................................................. .............. *435 405 840 [[Page 15072]]
200506.................................................. .............. 465 434 899
* Previous estimate of 425 has been corrected, based on subsequent location of 5 packs missed during survey period (Wydeven et al. 2006, pp. 910).
The 199798 survey concluded that approximately 2,445 wolves existed in about 385 packs in Minnesota during that winter period (90 percent confidence interval from 1,995 to 2,905 wolves) (Berg and Benson 1999, p. 4). This figure indicated the continued growth of the Minnesota wolf population at an average rate of about 3.7 percent annually from 1970 through 199798. Between 1979 and 1989 the annual growth rate was about 3 percent, and it increased to between 4 and 5 percent in the next decade (Berg and Benson 1999, 5, Fuller et al. 1992, p. 51). As of the 1998 survey, the number of Minnesota wolves was approximately twice the planning goal for Minnesota, as specified in the Eastern Recovery Plan (USFWS 1992, p. 28).
Minnesota DNR conducted another survey of the State's wolf population and range during the winter of 200304, again using similar methodology. That survey concluded that an estimated 3,020 wolves in 485 packs occurred in Minnesota at that time (90 percent confidence interval for this estimate is 2,301 to 3,708 wolves). Due to the wide overlap in the confidence intervals for the 199798 and 200304 surveys, the authors conclude that, although the population point estimate increased by about 24 percent over the 6 years between the surveys (about 3.5 percent annually), there was no statistically significant change in the State's wolf population during that period (Erb and Benson 2004, pp. 7 and 9).
As wolves increased in abundance in Minnesota, they also expanded their distribution. During 194853, the major wolf range was estimated to be about 11,954 sq mi (31,080 sq km) (Stenlund 1955, p. 19). A 1970 questionnaire survey resulted in an estimated wolf range of 14,769 sq mi (38,400 sq km) (calculated by Fuller et al. 1992, p. 43, from Leirfallom 1970). Fuller et al. (1992, p. 44), using data from Berg and Kuehn (1982), estimated that Minnesota primary wolf range included 14,038 sq mi (36,500 sq km) during winter 197879. By 198283, pairs or breeding packs of wolves were estimated to occupy an area of 22,000 sq mi (57,050 sq km) in northern Minnesota (Mech et al. 1988, p. 86). That study also identified an additional 15,577 sq mi (40,500 sq km) of peripheral range, where habitat appeared suitable but no wolves or only lone wolves existed. The 198889 study produced an estimate of 23,165 sq mi (60,200 sq km) as the contiguous wolf range at that time in Minnesota (Fuller et al. 1992, pp. 4849; Berg and Benson 1999, p. 3, 5), an increase of 65 percent over the primary range calculated for 197879. The 199798 study concluded that the contiguous wolf range had expanded to 33,971 sq mi (88,325 sq km), a 47 percent increase in 9 years (Berg and Benson 1999, p. 5). By that time the Minnesota wolf population was using most of the occupied and peripheral range identified by Mech et al. (1988, p. 86). The wolf population in Minnesota had recovered to the point that its contiguous range covered approximately 40 percent of the State during 199798. In contrast, the 200304 survey failed to show a continuing expansion of wolf range in Minnesota, and any actual increase in wolf numbers since 199798 was attributed to increased wolf density within a stabilized range (Erb and Benson 2004, p. 7).
Although Minnesota DNR does not conduct a formal wolf population survey annually, it includes the species in its annual carnivore track survey. This survey, standardized and operational since 1994, provides an annual index of abundance for several species of large carnivores by counting their tracks along 51 standardized survey routes in the northern portion of Minnesota. Based on these surveys, the wolf track indices for winter 200405 showed little change from the previous winter, and no statistically significant trends are apparent since 1994. However, the data show some indication of an increase in wolf density (Erb 2005, p. 2, 5). Thus, the winter track survey results are consistent with a stable or slowly increasing wolf population in northern Minnesota over this 11year period.
Wisconsin Recovery
Wolves were considered to have been extirpated from Wisconsin by 1960. No formal attempts were made to monitor the State's wolf population from 1960 until 1979. From 1960 through 1975, individual wolves and an occasional wolf pair were reported. There is no documentation, however, of any wolf reproduction occurring in Wisconsin, and the wolves that were reported may have been dispersing animals from Minnesota.
Wolves are believed to have returned to Wisconsin in more substantial numbers around 1975, and the Wisconsin Department of Natural Resources (WI DNR) began wolf population monitoring in 197980 and estimated a statewide population of 25 wolves at that time (Wydeven and Wiedenhoeft 2000, pp. 151, 159). This population remained relatively stable for several years, then declined slightly to approximately 15 to 19 wolves in the mid1980s. In the late 1980s, the Wisconsin wolf population began an increase that has continued into 2006 (Wydeven et al. 2006, p. 35).
Wisconsin DNR intensively surveys its wolf population annually
using a combination of aerial, ground, and satellite radio telemetry,
complemented by snow tracking and wolf sign surveys (Wydeven et al.
2006, pp. 45). Wolves are trapped from May through September and
fitted with radio collars, with a goal of having at least one radio
collared wolf in about half of the wolf packs in Wisconsin. Aerial
locations are obtained from each functioning radiocollar about once
per week, and pack territories are estimated and mapped from the
movements of the individuals who exhibit localized patterns. From
December through March, the pilots make special efforts to visually
locate and count the individual wolves in each radiotracked pack. Snow
tracking is used to supplement the information gained from aerial
sightings and to provide pack size estimates for packs lacking a radio
collared wolf. Tracking is done by assigning survey blocks to trained
trackers who then drive snowcovered roads in their blocks and follow
all wolf tracks they encounter. Snowmobiles are used to locate wolf
tracks in more remote areas with few roads. The results of the aerial and
[[Page 15073]]
ground surveys are carefully compared to properly separate packs and to
avoid overcounting (Wydeven et al. 2006a, pp. 45). The number of
wolves in each pack is estimated based on the aerial and ground
observations made of the individual wolves in each pack over the winter.
Because the monitoring methods focus on wolf packs, lone wolves are likely undercounted in Wisconsin. As a result, the annual population estimates are probably slight underestimates of the actual wolf population within the State during the latewinter period. Fuller (1989, p. 19) noted that lone wolves are estimated to compose from 2 to 29 percent of the total population in the area. Also, these estimates are made at the low point of the annual wolf population cycle; the latewinter surveys produce an estimate of the wolf population at a time when most winter mortality has already occurred and before the birth of pups. Thus, Wisconsin wolf population estimates are conservative in two respects: They undercount lone wolves and the count is made at the annual low point of the population. This methodology is consistent with the recovery criteria established in the 1992 Recovery Plan, which established numerical criteria to be measured with data obtained by latewinter surveys.
From midSeptember 2005 through midApril 2006, 43 radio collars were active on Wisconsin wolves, including 38 packs. An estimated 465 to 502 wolves in 115 packs, including 16 to 17 wolves on Native American reservations, were in the State in early 2006, representing a 7 percent increase from 2005 (Wydeven et al. 2006, pp. 1, 6).
Wisconsin population estimates for 1985 through 2006 increased from 15 to 465502 wolves (see Table 1 above) and from 4 to 115 packs (Wydeven et al. 2006, pp. 1, 35). This represents an annual increase of 21 percent through 2000, and an average annual increase of 11 percent for the most recent 6 years.
In 1995, wolves were first documented in Jackson County, Wisconsin, well to the south of the northern Wisconsin area occupied by other Wisconsin wolf packs. The number of wolves in this central Wisconsin area has dramatically increased since that time. During the winter of 200405, there were 5356 wolves in 14 packs in the central forest wolf range (Zone 2 in the Wisconsin Wolf Management Plan; WI DNR 1999, p. 18) and an additional 1719 wolves in 7 packs in the marginal habitat in Zone 3, located between Zone 1 (northern forest wolf range) and Zones 2 and 4 (Wydeven et al. 2006, pp. 6, 33).
During the winter of 200203, 7 wolves were believed to be primarily occupying Native American reservation lands in Wisconsin (Wydeven et al. 2003, p. 9); this increased to 11 to 13 wolves in the winter of 200405 (Wydeven in litt. 2005) and 1617 in 200506. The 200506 animals consisted of 2 packs totaling 7 to 8 wolves on the Bad River Chippewa Reservation and a pack of 4 wolves on the Lac Courtes Oreilles Chippewa Reservation, both in northwestern Wisconsin. There also was a single pack of three wolves on the Lac du Flambeau Reservation and a twowolf pack on the Menominee Reservation, in north central and northeastern Wisconsin, respectively (Wydeven et al. 2006, pp. 27, 28, 33). Additional wolves have spent some time on the Red Cliff Chippewa Reservation, the St. Croix Chippewa Reservation, and the Ho Chunk Reservation in the last few years. It is likely that the Potowatomi Reservation lands will also host wolves in the near future (Wydeven in litt. 2005). Of these reservations the HoChunk, St. Croix Chippewa, and Potowatomi are composed mostly of scattered parcels of land, and are not likely to provide significant amounts of wolf habitat.
In 2002, wolf numbers in Wisconsin alone surpassed the Federal criterion for a second population, as identified in the 1992 Recovery Plan (i.e., 100 wolves for a minimum of 5 consecutive years, as measured by 6 consecutive latewinter counts). Furthermore, in 2004 Wisconsin wolf numbers exceeded the Recovery Plan criterion of 200 animals for 6 successive latewinter surveys for an isolated wolf population. The Wisconsin wolf population continues to increase, although the slower rates of increase seen since 2000 may be the first indications that the State's wolf population growth and geographic expansion are beginning to level off. Mladenoff et al. (1997, p. 47) and Wydeven et al. (1999, p. 49) estimated that occupancy of primary wolf habitat in Wisconsin would produce a wolf population of about 380 animals in the northern forest area of the State plus an additional 20 40 wolves in the central forest area. If wolves occupy secondary habitat (areas with a 1050 percent probability of supporting a wolf pack) in the State, their estimated population could be 50 percent higher or more (Wydeven et al. 1999, p. 49) resulting in a statewide population of 600 or more wolves.
Michigan Recovery
Wolves were extirpated from Michigan as a reproducing species long before they were listed as endangered in 1974. Prior to 1991, and excluding Isle Royale, the last known breeding population of wild Michigan wolves occurred in the mid1950s. However, as wolves began to reoccupy northern Wisconsin, the Michigan Department of Natural Resources (MI DNR) began noting single wolves at various locations in the UP of Michigan. In 1989, a wolf pair was verified in the central UP, and it produced pups in 1991. Since that time, wolf packs have spread throughout the UP, with immigration occurring from Wisconsin on the west and possibly from Ontario on the east. They now are found in every county of the UP, with the possible exception of Keweenaw County (Huntzinger et al. 2005, p. 6).
The MI DNR annually monitors the wolf population in the UP by intensive latewinter tracking surveys that focus on each pack. The UP is divided into seven monitoring zones, and specific surveyors are assigned to each zone. Pack locations are derived from previous surveys, citizen reports, and extensive ground and aerial tracking of radiocollared wolves. During the winter of 200405 at least 87 wolf packs were resident in the UP (Huntzinger et al. 2005, p. 6). A minimum of 40 percent of these packs had members with active radiotracking collars during the winter of 200405 (Huntzinger et al. 2005, p. 67). Care is taken to avoid doublecounting packs and individual wolves, and a variety of evidence is used to distinguish adjacent packs and accurately count their members. Surveys along the border of adjacent monitoring zones are coordinated to avoid doublecounting of wolves and packs occupying those border areas. In areas with a high density of wolves, ground surveys by 4 to 6 surveyors with concurrent aerial tracking are used to accurately delineate territories of adjacent packs and count their members (Beyer et al. 2004, pp. 23, Huntzinger et al. 2005, pp. 36; Potvin et al. 2005, p. 1661). As with Wisconsin, the Michigan surveys likely miss many lone wolves, thus underestimating the actual population.
Annual surveys have documented minimum latewinter estimates of
wolves occurring in the UP as increasing from 57 wolves in 1994 to 434
in 91 packs in 2006 (see Table 1 above). Over the last 10 years the
annualized rate of increase has been about 18 percent (Beyer et al. 2006, p. 35; Huntzinger et al. 2005, p. 6; MI DNR
[[Page 15074]]
2006a; Roell in litt. 2006a). The rate of annual increase has varied
from year to year during this period, but there appears to be two
distinct phases of population growth, with relatively rapid growth
(24.3 to 25.9 percent per year) from 1997 through 2000 and slower
growth (11.6 to 15.5 percent from 2000 through 2005 and 7.2 percent in
2006) since then. As with the Wisconsin wolves, the number of wolves in
the Michigan UP wolf population by itself has surpassed the recovery
criterion for a second population in the eastern United States (i.e.,
100 wolves for a minimum of 5 consecutive years, based on 6 latewinter
estimates), as specified in the Federal Recovery Plan, since 2001. In
addition, the UP numbers have now surpassed the Federal criterion for
an isolated wolf population of 200 animals for 6 successive latewinter surveys (USFWS 1992, pp. 2426).
To date, no wolf packs are known to be primarily using tribalowned lands in Michigan (Roell in litt. 2006b). Native American tribes in the UP of Michigan own small, scattered parcels of land. As such, no one tribal property would likely support a wolf pack. However, as wolves occur in all counties in the UP and range widely, tribal land is likely utilized periodically by wolves.
The wolf population of Isle Royale National Park, Michigan, is not considered to be an important factor in the recovery or longterm survival of wolves in the WGL DPS. This is a small and isolated wolf population that probably has not had any contact with mainland wolf populations since its founding pair crossed the Lake Superior ice in the late 1940s (Peterson et al. 1998, p. 828). This wolf population lacks sufficient genetic uniqueness (Wayne et al. 1991, pp. 4749), and due to the island's small size, cannot satisfy the discreteness criterion for a separate DPS. For these same reasons it will not make a significant numerical contribution to gray wolf recovery, although longterm research on this wolf population has added a great deal to our knowledge of the species. The wolf population on Isle Royale has ranged from 12 to 50 wolves since 1959, and was 30 wolves in the winter of 200506 (Peterson and Vucetich 2006, p. 6).
Although there have been verified reports of wolf sightings in the Lower Peninsula of Michigan, resident breeding packs have not been confirmed there. In October 2004 the first gray wolf since 1910 was documented in the Lower Peninsula (LP). This wolf had been trapped and radiocollared by the MI DNR while it was a member of a central UP pack in late 2003. At some point it had moved to the LP and ultimately was killed by a trapper who believed it was a coyote (MI DNR 2004). Shortly after that, MI DNR biologists and conservation officers confirmed that two additional wolves were traveling together in Presque Isle County in the northern Lower Peninsula (NLP). A subsequent twoweek survey was conducted in that area, but no additional evidence of wolf presence was found (Huntzinger et al. 2005, p. 35). Recognizing the likelihood that small numbers of gray wolves will eventually move into the Lower Peninsula and form persistent packs (Potvin 2003, pp. 2930, Gehring and Potter 2005, p. 1242; Beyer et at. 2006, p. 35), MI DNR has begun a revision of its Wolf Management Plan in part to incorporate provisions for wolf management there.
Summary for Wisconsin and Michigan
The twoState wolf population, excluding Isle Royale wolves, has exceeded 100 wolves since latewinter 199394 and has exceeded 200 wolves since latewinter 199596. Therefore, the combined wolf population for Wisconsin and Michigan has exceeded the second population recovery goal of the 1992 Recovery Plan for a nonisolated wolf population since 1999. Furthermore, the twoState population has exceeded the recovery goal for an isolated second population since 2001.
Other Areas in and Near the Western Great Lakes DPS
As described earlier, the increasing wolf population in Minnesota and the accompanying expansion of wolf range westward and southwestward in the State have led to an increase in dispersing wolves that have been documented in North and South Dakota in recent years. No surveys have been conducted to document the number of wolves present in North Dakota or South Dakota. However, biologists who are familiar with wolves there generally agree that there are only occasional lone dispersers that appear primarily in the eastern portion of these States. There were reports of pups being seen in the Turtle Mountains of North Dakota, in 1994 (Collins in litt. 1998), an adult male wolf was shot near Devil's Lake, North Dakota in 2002, another adult male shot in Richland County in extreme southeastern North Dakota in 2003 (Fain in litt. 2006), and a vehiclekilled adult male found near Sturgis, South Dakota, in 2006 (Larson in litt. 2006a). In contrast to the other South Dakota wolves of the last twentyfive years, this animal has been genetically identified as having come from the Greater Yellowstone area (Fain in litt. 2006). See the Delineating the WGL Gray Wolf DPS for a detailed discussion of movement of wolves.
Wolf dispersal is expected to continue as wolves travel away from the more saturated habitats in the core recovery areas into areas where wolves are extremely sparse or absent. Unless they return to a core recovery population and join or start a pack there, they are unlikely to contribute to longterm maintenance of recovered wolf populations. Although it is possible for them to encounter a mature wolf of the opposite sex, to mate, and to reproduce outside the core wolf areas, the lack of large expanses of unfragmented public land make it unlikely that any wolf packs will persist in these areas, and this is a bottleneck that seriously impedes further expansion. The only exception is the NLP of Michigan, where several studies indicate that a persistent wolf population may develop (Gehring and Potter 2005, p. 1242; Potvin 2003, 2930), perhaps dependent on occasional to frequent immigration of UP wolves. However, currently existing wolf populations in Minnesota, Wisconsin, and the UP of Michigan have already greatly exceeded the Federal recovery criteria and are not dependent on wolves or wolf populations from other areas of the WGL DPS to maintain these recovered numbers.
Previous Federal Action
On April 1, 2003, we published a final rule revising the listing
status of the gray wolf across most of the conterminous United States
(68 FR 15804). Within that rule, we identified three distinct
population segments (DPS) for the gray wolf. Gray wolves in the Western
DPS and the Eastern DPS were reclassified from endangered to
threatened, except where already classified as threatened or as an
experimental population. Gray wolves in the Southwestern DPS retained
their previous endangered or experimental population status. Three
existing gray wolf experimental population designations were not
affected by the April 1, 2003, final rule. We removed gray wolves from
the lists of threatened and endangered wildlife in all or parts of 16
southern and eastern States where the species historically did not
occur. We also established a new special rule under section 4(d) of the
Act for the threatened Western DPS to increase our ability to
effectively manage wolfhuman conflicts outside the two experimental
population areas in the Western DPS. In addition, we established a
second section 4(d) rule that applied provisions similar to those [[Page 15075]]
previously in effect in Minnesota to most of the Eastern DPS. These two
special rules were codified in 50 CFR 17.40(n) and (o), respectively.
On January 31, 2005, and August 19, 2005, U.S. District Courts in Oregon and Vermont, respectively, ruled that the April 1, 2003, final rule violated the Act (Defenders of Wildlife v. Norton, 031348JO, D. OR 2005; National Wildlife Federation v. Norton, 1:03CV340, D. VT. 2005). The Courts' rulings invalidated the revisions to the gray wolf listing. Therefore, the status of gray wolves outside of Minnesota and outside of areas designated as nonessential experimental populations reverted back to endangered (as had been the case prior to the 2003 reclassification). The courts also invalidated the three DPSs identified in the April 1, 2003, rule as well as the associated special regulations.
On March 27, 2006, we published a proposal (71 FR 1526615305) to identify a WGL DPS of the gray wolf, to remove the WGL DPS from the protections of the Act, to remove designated critical habitat for the gray wolf in Minnesota and Michigan, and to remove special regulations for the gray wolf in Minnesota. The proposal was followed by a 90day comment period, during which we held four public hearings on the proposal.
On February 8, 2007, we published a final rule identifying a WGL DPS of the gray wolf, removing the WGL DPS from the protections of the Act, removing designated critical habitat for the gray wolf in Minnesota and Michigan, and removing special regulations for the gray wolf in Minnesota (72 FR 6052).
On April 16, 2007, three parties filed a lawsuit against the U.S.
Department of the Interior (Department) and the Service, challenging
the Service's February 8, 2007 (72 FR 6052), identification and
delisting of the WGL DPS. The plaintiffs argued that the Service may
not identify a DPS within a broader preexisting listed entity for the
purpose of delisting the DPS. Based on this argument, the U.S. District
Court for the District of Columbia remanded and vacated the February 7,
2008, WGL DPS final rule (72 FR 6052). The court found that the Service
had made that decision based on its interpretation that the plain
meaning of the ESA authorizes the Service to identify and delist a DPS
within an alreadylisted entity. The court disagreed, and concluded
that the Act is ambiguous as to whether the Service has this authority.
The court accordingly remanded the final rule so that the Service can
provide a reasoned explanation of how its interpretation is consistent with the text, structure, legislative history, judicial
interpretations, and policy objectives of the Act (Humane Society of
the United States v. Kempthorne, Civ. No. 070677, 2008 U.S. Dist. LEXIS 74495 (D.D.C. Sept. 29, 2008) (J. Friedman).
On December 11, 2008, we published a notice reinstating protections for the gray wolf in the western Great Lakes and northern Rocky Mountains pursuant to courtorders (73 FR 75356).
Please refer to the March 27, 2006, (71 FR 1526615305) proposed rule for further information on previous Federal actions.
Issues on Remand
In an Opinion dated September 29, 2008, the United States District Court for the District of Columbia vacated the final rule (72 FR 6052) (Feb. 8, 2007) identifying the Western Great Lakes Distinct Population Segment of gray wolf and delisting that DPS. The Humane Society of the United States v. Kempthorne, Civ. No. 070677, 2008 U.S. Dist. LEXIS 74495 (D.D.C. Sept. 29, 2008) (J. Friedman). Judge Friedman remanded the matter to the Secretary to allow the agency to ``bring its expertise and experience to bear on the question of whether the Act permits it to use the DPS tool in the fashion it has proposed.'' Id. at *40. Judge Friedman instructed that the agency must explain how the agency's interpretation of the statute conforms to the text, structure, and legislative history of the ESA; how the agency's interpretation is consistent with judicial interpretations of the Act, if any; and how the agency's interpretation serves the Act's policy objectives. Id. In so doing, Judge Friedman did not find that the Service could not utilize the DPS tool to simultaneously identify and delist a DPS. Instead, Judge Friedman found that the record lacked an explanation on this point to which he could defer under Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (1984), and afforded the agency an opportunity to respond.
While the Service acknowledges that the ESA is arguably ambiguous on the ``precise question'' posed by the court, it notes that the court's question does not accurately describe what we did in the Final Rule. What we actually did, under the precise language of the Act, was to determine, pursuant to section 4(a)(1), that gray wolves in the Western Great Lakes area constituted a DPS and that the DPS was neither endangered nor threatened, and then revised the List of Endangered and Threatened Wildlife, pursuant to section 4(c)(1), to reflect those determinations. Our conclusion is that we had clear authority to make the determinations and the revisions. We did not delist a previously unlisted species; rather, we revised the existing listing of a species (the gray wolf in the lower 48 States) to reflect a determination that a subpart of that species (the Western Great Lakes DPS) was healthy enough that it no longer needed the ESA's protections. Our authority to make these determinations and to revise the list accordingly is found in the precise language of the ESA. Moreover, even if that authority was not clear, our interpretation of this authority to make determinations under section 4(a)(1) and to revise the endangered and threatened species list to reflect those determinations under section 4(c)(1) is reasonable and fully consistent with the ESA's text structure, legislative history, relevant judicial interpretations, and policy objectives.
By vacating the previous final rule and remanding the rulemaking to the Service, the court required the Service to make a new final determination on the March 27, 2006 proposed rule (71 FR 15266) on which the vacated final rule was based. In that proposed rule, the Service provided public notice of its consideration of identifying the Western Great Lakes Distinct Population Segment of gray wolves and to remove that DPS from the List of Endangered and Threatened Wildlife. At that time, the Service requested public comments on the proposal and received 360 comments addressing a wide range of issues, including but not limited to the Service's use of the DPS tool in the manner proposed. Comments were received from 40 identifiable states, 5 foreign countries, 19 preservation and conservation organizations, 16 agricultural and livestock organizations, 249 private individuals, and 6 Native American governments or organizations. All of these comments were given meaningful consideration in the course of the Secretary promulgating this final rule.
This final rule constitutes a new final determination on the March
27, 2006 proposed rule. It is also substantially similar to the vacated
final rule in form and substance, including the biological and
ecological basis for its conclusions. This final rule differs in that
it contains a section entitled ``Issues on Remand'' that represents the
Secretary's response to the issues raised by the Court, in consultation
with the Department of the Interior's Solicitor's Office. This section
of the final rule merely addresses the narrow legal issue within the
agency's expertise and experiencenamely, whether the Secretary may
simultaneously identify and delist a currently listed species. The section
[[Page 15076]]
entitled Distinct Vertebrate Population Segment Policy Overview
responds to the court's question regarding the agency's past practice and use of DPSs.
Before issuing this final rule, we verified that no new scientific data exist that would alter our previous analysis of the relevant facts that serve as the basis for the Secretary's decision to identify the Western Great Lakes DPS and the Secretary's conclusion that the Western Great Lakes DPS should be removed from the list of threatened and endangered species because it has recovered and no longer meets the criteria for remaining on the list. Note that we did examine updated monitoring data and the final Michigan plan and determined that this new data merely supplements our existing record. The Service is simply responding to the narrow legal issues raised by the Court. Consequently, Section 553(b)(3)(B) of the Administrative Procedure Act (APA) does not require an additional period of public notice and comment.
We consulted with the Solicitor of the Department of the Interior to address the issue in Judge Friedman's opinion that the agency must explain how our interpretation of the statute conforms to the text, structure, and legislative history of the ESA; is consistent with judicial interpretations of the Act, if any; and serves the Act's policy objectives. On December 12, 2008, a formal opinion was issued by the Solicitor, ``U.S. Fish and Wildlife Service Authority Under Section 4(c)(1) of the Endangered Species Act to Revise Lists of Endangered and Threatened Species to `Reflect Recent Determinations' '' (U.S. DOI 2008), which fully addresses these issues. The Service fully agrees with the analysis and conclusions set out in the Solicitor's opinion. This action is consistent with the opinion. The complete text of the Solicitor's opinion can be found at http://www.fws.gov/midwest/wolf/. Geographical Area of the Western Great Lakes Distinct Population Segment
The geographical area of the WGL DPS is shown in Figure 1, below,
and is described as all of Minnesota, Wisconsin, and Michigan; the
portion of North Dakota north and east of the Missouri River upstream
to Lake Sakakawea and east of the centerline of Highway 83 from Lake
Sakakawea to the Canadian border; the portion of South Dakota north and
east of the Missouri River; the portions of Iowa, Illinois, and Indiana
north of the centerline of Interstate Highway 80; and the portion of
Ohio north of the centerline of Interstate Highway 80 and west of the Maumee River at Toledo.
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Distinct Vertebrate Population Segment Policy Overview
Pursuant to the Act, we consider if information is sufficient to indicate that listing, reclassifying, or delisting any species, subspecies, or, for vertebrates, any DPS of these taxa may be warranted. To interpret and implement the DPS provision of the Act and congressional guidance, the Service and the National Marine Fisheries Service (NMFS) published a policy regarding the identification of distinct vertebrate population segments under the Act (61 FR 4722, February 7, 1996). Under this policy, two factors are considered in a decision regarding the potential identification of a DPS and then a final factor is considered regarding the listing, reclassification, or delisting of the DPS. The first two factors determine whether the population segment is a valid DPS(1) discreteness of the population segment in relation to the remainder of the taxon, and (2) the significance of the population segment to the taxon to which it belongs. If a population meets both tests, it can be identified as a DPS. Then the third factor, the population segment's conservation status, is evaluated in relation to the Act's standards for listing, delisting, or reclassification (i.e., is the DPS endangered or threatened).
Agency's Past Practice and History of Using DPSs
Of the over 370 native vertebrate ``species'' listed under the Act,
77 are listed as less than an entire taxonomic species or subspecies
(henceforth referred to as populations) under one of several
authorities including the DPS language in the definition of
``species''. Of these 77 listed populations, 32 predate the 1996 DPS
policy (61 FR 4722); therefore, the final listing determinations for
these populations did not include formal DPS analyses per the 1996 DPS
policy. Specifically, the 77 populations encompass 51 different species
or subspecies. During the history of the Act, the Service and NMFS have taken actions with respect
[[Page 15078]]
to populations in 98 listing, reclassification, and delisting actions.
The majority of those actions identified a classification other than a
taxonomically recognized species or subspecies at the time of listing.
In several instances, however, the agencies have identified a DPS and,
as appropriate, revised the list of Threatened and Endangered Wildlife
in a single action. For example, we (1) established a DPS of the
grizzly bear (Ursus arctos horribilis) for the Greater Yellowstone Area
and surrounding area, within the existing listing of the grizzly bear
in the lower 48 States, and removed this DPS from the List of
Threatened and Endangered Wildlife (March 29, 2007; 72 FR 14865); (2)
established two DPSs of the Columbian whitetailed deer (Odocoileus
virginianus leucurus): the Douglas County DPS and the Columbia River
DPS; and removed the Douglas County DPS from the List of Threatened and
Endangered Wildlife (July 24, 2003; 68 FR 43647); (3) removed the brown
pelican (Pelecanus occidentalis) in the Southeastern United States from
the List of Endangered and Threatened Wildlife and continued to
identify the brown pelican as endangered throughout the remainder of
its range (February 4, 1985; 50 FR 4938); (4) identified the American
crocodile (Crocodylus acutus) in Florida as a DPS within the existing
endangered listing of the American crocodile in the United States and
reclassified the Florida DPS from endangered to threatened (March 20,
2007; 71 FR 13027); and (5) amended the List of Endangered and
Threatened Wildlife and Plants by revising the entry for the gray whale
(Eschrichtius robustus) to remove the eastern North Pacific population
from the List while retaining the western North Pacific population as
endangered (June 16, 1994; 59 FR 31094)). We also proposed in 2000 to
identify four DPSs within the existing listing of the gray wolf in the
lower 48 States and to reclassify three of the DPSs from endangered to
threatened (July 13, 2000; 65 FR 43450). As described above under
``Previous Federal Action,'' the final rule we issued in 2003
identified three gray wolf DPSs and reclassified two of the DPSs from
endangered to threatened (April 1, 2003; 68 FR 15804). Although courts
subsequently invalidated these DPSs, they did not question the
Service's authority to identify and reclassify DPSs within a larger
preexisting listing. Identifying and delisting the Western Great Lakes
DPS of gray wolves is consistent with the Service's past practice and does not represent a change in agency position.
Analysis for Discreteness
Under our Policy Regarding the Recognition of Distinct Vertebrate Population Segments, a population segment of a vertebrate taxon may be considered discrete if it satisfies either of the following conditions(1) it is markedly separated from other populations of the same taxon as a consequence of physical, physiological, ecological, or behavioral factors (quantitative measures of genetic or morphological discontinuity may provide evidence of this separation); or (2) it is delimited by international governmental boundaries within which differences in control of exploitation, management of habitat, conservation status, or regulatory mechanisms exist that are significant in light of section 4(a)(1)(D) of the Act.
Markedly Separated From Other Populations of the TaxonThe western boundary of the WGL DPS is approximately 400 mi (644 km) from the nearest known wolf packs in Wyoming and Montana. The distance between those western packs and the nearest packs within the WGL DPS is nearly 600 miles (966 km). The area between Minnesota packs and Northern Rocky Mountain packs largely consists of unsuitable habitat, with only scattered islands of possibly suitable habitat, such as the Black Hills of eastern Wyoming and western South Dakota. There are no known gray wolf populations to the south or east of the WGL DPS.
As discussed in the previous section, gray wolves are known to disperse over vast distances, but straight line documented dispersals of 400 mi (644 km) or more are very rare. While we cannot rule out the possibility of a Midwest wolf traveling 600 miles or more and joining or establishing a pack in the Northern Rockies, such a movement has not been documented and is expected to happen very infrequently, if at all. Similar movements from the NRM wolf population into the WGL DPS are unknown and are expected to happen infrequently. The 2006 Sturgis, South Dakota, wolf is the closest that an NRM wolf has come to entering the WGL DPS (Fain in litt. 2006). However, the Sturgis wolf still had over 300 mi (500 km) to travel before it would encounter the nearest WGL DPS wolf pack. As the discreteness criterion requires that the DPS be ``markedly separated'' from other populations of the taxon rather than requiring complete isolation, this high degree of physical separation between the Western Great Lakes and the Northern Rocky Mountains satisfies the discreteness criterion. Similarly, we feel it is unlikely for wolves to cross the eastern boundary into the Laurentian Mixed Habitat Province of New York, Pennsylvania, and New England due to inhospitable conditions.
Delimited by International Boundaries with Significant Management Differences Between the U.S. and CanadaThis border has been used as the northern boundary of the listed entity since gray wolves were reclassified in the 48 States and Mexico in 1978. There remain significant crossborder differences in exploitation, management, conservation status, and regulatory mechanisms. More than 50,000 wolves exist in Canada, where suitable habitat is abundant, human harvest of wolves is common, Federal protection is absent, and provincial regulations provide widely varying levels of protection. In general, Canadian wolf populations are sufficiently large and healthy so that harvest and population regulation, rather than protection and close monitoring, is the management focus. There are an estimated 4,000 wolves in Manitoba (Manitoba Conservation undated). Hunting is allowed nearly provincewide, including in those provincial hunting zones adjoining northwestern Minnesota, with a current season that runs from August 28, 2006, through March 31, 2007 (Manitoba Conservation 2006a). Trapping wolves is allowed provincewide except in and immediately around Riding Mountain National Park (southwestern Manitoba), with a current season running from October 14, 2006, through February 28 or March 31, 2007 (varies with trapping zone) (Manitoba Conservation 2006b). The Ontario Ministry of Natural Resources estimates there are 8,850 wolves in the province, based on prey composition and abundance, topography, and climate. Wolf numbers in most parts of the province are believed to be stable or increasing since about 1993 (Ontario MNR 2005a, pp. 79). In 2005 Ontario limited hunting and trapping of wolves by closing the season from April 1 through September 14 in central and northern Ontario (Ontario MNR 2005b). In southern Ontario (the portion of the province that is adjacent to the WGL DPS), wolf hunting and trapping is permitted year around except within, and immediately around, Algonquin Provincial Park in southeastern Ontario (north of Lake Ontario) where seasons are closed all year (Ontario MNR 2005c).
We, therefore, conclude that the abovedescribed WGL DPS boundary
satisfies both conditions that can be used to demonstrate discreteness of a potential DPS.
[[Page 15079]]
Analysis for Significance
If we determine that a population segment is discrete, we next consider available scientific evidence of its significance to the taxon to which it belongs. Our DPS policy states that this consideration may include, but is not limited to, the following(1) persistence of the discrete population segment in an ecological setting unusual or unique for the taxon; (2) evidence that loss of the discrete population segment would result in a significant gap in the range of the taxon; (3) evidence that the discrete population segment represents the only surviving natural occurrence of a taxon that may be more abundant elsewhere as an introduced population outside its historic range; and/ or (4) evidence that the discrete population segment differs markedly from other populations of the species in its genetic characteristics. Below we address Factors 1 and 2. Factors 3 and 4 do not apply to the WGL wolf DPS and thus are not included in our analysis for significance.
Unusual or Unique Ecological SettingWolves within the WGL DPS occupy the Laurentian Mixed Forest Province, a biotic province that is transitional between the boreal forest and the broadleaf deciduous forest. Laurentian Mixed Forest consists of mixed coniferdeciduous stands, pure deciduous forest on favorable sites, and pure coniferous forest on less favorable sites. Within the United States this biotic province occurs across northeastern Minnesota, northern Wisconsin, the UP, and the NLP, as well as the eastern half of Maine, and portions of New York and Pennsylvania (Bailey 1995). In the Midwest, current wolf distribution closely matches this province, except for the NLP and the Door Peninsula of Wisconsin, where wolf packs currently are absent. To the best of our knowledge, wolf packs currently do not inhabit the New England portions of the Laurentian Mixed Forest Province, nor do we expect wolves from the WGL DPS to move into them due to the vast distance between these two areas and inhospitable terrain they would need to traverse. Therefore, WGL wolves represent the only wolf packs in the United States occupying this province. Furthermore, WGL wolves represent the only use by gray wolf packs of any form of eastern coniferous or eastern mixed coniferousbroadleaf forest in the United States.
Significant Gap in the Range of the TaxonThis factor may be primarily of value when considering the initial listing of a taxon under the Act to prevent the development of a major gap in a taxon's range (``the loss of the discrete population segment would result in a significant gap in the range of the taxon'' (61 FR 4725)). However, this successful restoration of a viable wolf metapopulation to large parts of Minnesota, Wisconsin, and Michigan has filled a significant gap in the historical range of the wolf in the United States, and it provides an important extension of the range of the North American gray wolf population. The recovered Western Great Lakes wolf metapopulation is the only wolf population in the conterminous States east of the Rocky Mountains except for the red wolves being restored along the Atlantic Coast and currently holds about 80 percent of North American gray wolves that occur south of Canada.
Discrete Vertebrate Population Segment Conclusion
We conclude, based on our review of the best available scientific data, that the WGL DPS is discrete from other wolf populations as a result of physical separation and the international border with Canada. The DPS is significant to the taxon to which it belongs because it contains the only populations of the species in the Laurentian Mixed Forest Biotic Province in the United States, it contains a wolf metapopulation that fills a large gap in the historical range of the taxon; and it contains the majority of gray wolves in the conterminous States. Therefore, we have determined that this population segment of wolves satisfies the discreteness and significance criteria required to identify it as a DPS. The evaluation of the appropriate conservation status for the WGL DPS is found below.
Delineating the WGL Gray Wolf DPS
In contrast to a species or a subspecies, a DPS is a biological population that is delineated by a boundary that is based on something other than established taxonomic distinctions. Therefore, the starting point for delineating a DPS is the biological population or metapopulation, and a geographical delineation of the DPS must reasonably represent the population/metapopulation and its biological characteristics.
To delineate the boundary of the WGL DPS, we considered the current distribution of wolves in the Midwest and the characteristic movements of those wolves and of gray wolves elsewhere. We examined the available scientific data on longdistance movements, including longdistance movements followed by return movements to the vicinity of the natal pack. We concluded that wolf behavior and the nature of wolf populations require that we include within the area of the DPS some subset of known longdistance movement locations. However, as described below, wolf biology and common sense argue against the inclusion within the DPS boundary of all known or potential longdistance movements.
This analysis resulted in a WGL DPS boundary that is shown in Figure 1. As discussed below, this DPS has been delineated to include the core recovered wolf population plus a wolf movement zone around the core wolf populations. This geographic delineation is not intended to include all areas to which wolves have moved from the Great Lakes population. Rather, it includes the area currently occupied by wolf packs in Minnesota, Wisconsin, and Michigan; the nearby areas in these States, including the Northern Lower Peninsula of Michigan, in which wolf packs may become established in the foreseeable future; and a surrounding area into which Minnesota, Wisconsin, and Michigan wolves occasionally move but where persistent packs are not expected to be established because suitable habitat is rare and exists only as small patches. The area surrounding the core wolf populations includes the locations of most known dispersers from the core populations, especially the shorter and mediumdistance movements from which wolves are most likely to return to the core areas and contribute to the recovered wolf population.
The WGL areas that are regularly occupied by wolf packs are well
documented in Minnesota (Erb and Benson 2004, p. 12, fig. 3), Wisconsin
(Wydeven et al. 2006, p. 33, fig. 1), and the UP of Michigan (Huntzinger et al. 2005, pp. 2527, figs. 46). Wolves have
successfully colonized most, perhaps all, suitable habitat in
Minnesota. Minnesota data from the winter of 200304 indicate that wolf
numbers and density either have continued to increase slowly or have
stabilized since 199798, and there was no expansion of occupied range
in the State (Erb and Benson 2004, p. 7). Wisconsin wolves now occupy
most habitat areas believed to have a high probability of wolf
occurrence except for some areas of northeastern Wisconsin, and the
State's wolf population continues to annually increase in numbers and,
to a lesser degree, in area (Wydeven et al. 2006, p. 33). The UP of
Michigan has wolf packs throughout, although the current population
remains well below the estimated biological carrying capacity (Mladenoff et al. 1997, pp. 2527, and
[[Page 15080]]
figs. 5 & 7) and will likely continue to increase in numbers in the UP for at least several more years.
When delineating the WGL DPS, we had to consider the high degree of mobility shown by wolves. The dispersal of wolves from their natal packs and territories is a normal and important behavioral attribute of the species that facilitates the formation of new packs, the occupancy of vacant territories, and the expansion of occupied range by the ``colonization'' of vacant habitat. Data on wolf dispersal rates from numerous North American studies (summarized in Fuller et al. 2003, p. 179, Table. 6.6; Boyd and Pletscher 1999, p. 1102, Table 6) show dispersal rates of 13 to 48 percent of the individuals in a pack. Sometimes the movements are temporary, and the wolf returns to a location in or near its natal territory. In some cases a wolf may continue its movement for scores or even hundreds of miles until it locates suitable habitat, where it may establish a territory or join an existing pack. In other cases, a wolf is found dead at a distance from its original territory, leaving unanswered the questions of how far it would have gone and whether it eventually would have returned to its natal area or population.
MinnesotaThe current record for a documented extraterritorial movement by a gray wolf in North America is held by a Minnesota wolf that moved a minimum (that is, the straight line distance from known starting point to most distant point) of at least 550 mi (886 km) northwest into Saskatchewan (Fritts 1983, p. 166167). Nineteen other primarily Minnesota movements summarized by Mech (in litt. 2005) averaged 154 mi (248 km). Their minimum distance of travel ranged from 32532 mi (53886 km) with the minimum dispersal distance shown by known returning wolves ranging from 54 mi (90 km) to 307 mi (494 km).
WisconsinIn 2004, a wolf tagged in Michigan was killed by a vehicle in Rusk County in northwestern Wisconsin, 295 miles (475 km) west of his original capture location in the eastern UP (Wydeven et al. 2005b, p. 4). A similar distance (298 mi, 480 km) was traveled by a northcentral Wisconsin yearling female wolf that moved to the Rainy Lake region of Ontario during 198889 (Wydeven et al. 1995, p. 149).
MichiganDrummer et al. (2002, pp. 1415) reported 10 long distance dispersal events involving UP wolves. One of these wolves moved to northcentral Missouri and another to southeastern Wisconsin, both beyond the core wolf areas in the WGL. The average straightline distance traveled by those two wolves was 377 mi (608 km), while the average straightline distance for all 10 of these wolves was 232 mi (373 km). Their straightline distances ranged from 41 to 468 mi (66 to 753 km).
Illinois and IndianaThe December 2002, Marshall County, Illinois, wolf likely dispersed from the Wisconsin wolf population, nearly 200 miles (322 km) to the north (Great Lakes Directory 2003). The Randolph County, Indiana wolf had traveled a minimum distance of at least 420 miles (676 km) to get around Lake Michigan from its central Wisconsin birthplace; it likely traveled much farther than that unless it went through the city or suburbs of Chicago (Wydeven et al. 2004, pp. 10 11). The Pike County, Illinois, wolf that was shot in late 2005 was about 300 mi (180 km) from the nearest wolf packs in central Wisconsin.
North Dakota, South Dakota, and NebraskaLicht and Fritts (1994, p. 77) tabulated seven gray wolves found dead in North Dakota and South Dakota from 1981 through 1992 that are believed to have originated from Minnesota, based on skull morphometrics. Although none of these wolves were marked or radiotracked, making it impossible to determine the point of initiation of their journey, a minimum travel distance for the seven of Minnesota origin can be determined from the nearest wolf breeding range in Minnesota. For the seven, the average distance to the nearest wolf breeding range was 160 mi (257 km) and ranged from 29 to 329 mi (46 to 530 km). One of these seven wolves moved west of the Missouri River before it died.
Genetic analysis of a wolf killed in Harding County, in extreme northwestern South Dakota, in 2001 indicated that it originated from the MinnesotaWisconsinMichigan wolf populations (Fain in litt. 2006). The straightline travel distance to the nearest Minnesota wolf pack is nearly 400 miles (644 km).
The wolf from the Greater Yellowstone area that was killed by a vehicle on Interstate 90 near Sturgis, SD, in March of 2006 traveled a minimum straightline distance of about 270 mi (435 km) from the nearest known Greater Yellowstone pack before it died (USFWS et al. 2006, in USFWS Program Report, Figure 1).
A large canid was shot by a Boyd County, Nebraska, rancher in late 1994 or early 1995, likely after crossing the frozen Missouri River from South Dakota (Anschutz in litt. 2006, Jobman in litt. 1995). It was determined to be a wolf that originated from the Great Lakes wolf populations (Fain in litt. 2006), whose nearest pack would have been about 300 mi (480 km) away. A wolf illegally killed near Spalding, Nebraska, in December of 2002 also originated from the Minnesota WisconsinMichigan wolf population, as determined by genetic analysis (Anschutz in litt. 2003, Fain in litt. 2006). The nearest Minnesota wolf pack is nearly 350 miles (563 km) from this location.
Other notable extraterritorial movementsNotable are several wolves whose extraterritorial movements were radiotracked in sufficient detail to provide insight into their actual travel routes and total travel distances for each trek, rather than only documenting straightline distance from beginning to endpoint. Merrill and Mech (2000, pp. 429431) reported on four such Minnesota wolves with documented travel distances ranging from 305 to 2,641 mi (490 to 4,251 km) and an average travel route length of
FOR FURTHER INFORMATION CONTACT
Laura Ragan, 612-713-5350. Direct all
questions or requests for additional information to: GRAY WOLF
QUESTIONS, U.S. Fish and Wildlife Service, Federal Building, 1 Federal
Drive, Ft. Snelling, Minnesota 551114056. Additional information is
also available on our World Wide Web site at http://www.fws.gov/
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